Dumb error regarding Recovery

I did something really stupid. A fatal (disk?) error prevented the system from booting so I attempted to recovery of the critical portions of Windows 7. Unfortunately there are two options (one is called Recovery, the other is called something similar). I though I was refreshing only a components of a corrupted nucleus and it turned out to be a complete reinstall of the original OS along with original software.

I realized my mistake and stopped the process but the root directory structure had already been updated so the HD is trashed. I switched disks and rebuild on a different drive and everything is working. Then when I attempted to reinstall from my backup, I found the DVDs unreadable.

I know much of the data on the old disk is unrecoverable but on the TV Cop shows, experts regularly scan an old hard drive and recover some portions of old files (which is not the same as unerase in a fully intact file structure. Does anybody know of software that will ignore the updated root file structure and scan the unaltered portions of the disk for files I might still be able to recover?